Within the String, if you want to use \ as an actual character, you must precede it with another \, because \ is the escape symbol. The compiler is telling you in this case that it doesn't recognize the escape sequences like \P.

But the broswer won't bring up the HTML document. I am running Orion, so how should I code the link to the servlet class? The Cattle Drive code page showed the URL using "servlet/classname" and that didn't work either. So it is possible to link a servlet like that? The Head First book was not too clear on this.